Temperature controlling device



May 13, 1947.

H. S. BURLING TEMPERATURE CONTROLLING DEVICE Filed Nov. 9, 1945 INVENTORATTORNEY Patented May 13, 1947 UNITED' STATES PATENT OFFICE 1TEMPERATURE CONTROLLING DEVICE Herbert s. Burling, South m. N. J.Application November 9, 1945, Serial No. 627,586

The present invention relates to improvements in temperature controllingmechanisms, and more particularly in mechanisms adapted to control thetemperatures in chambers requiring exact temperature regulation, such asthose used inmany industrial and laboratory processes and research.

Objects and advantages 0! the invention will be set forth in parthereinafter and in part will be obvious hereirom, or may be learned bypractice with the invention, the same being realized and attained bymeans of the instrumentallties and combinations pointed out in theappended claims.

The invention consists in the novel parts, constructions, arrangements,combinations, and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a parthereof, illustrate one embodiment oi the invention, and together withthe description, serve to explain the principles of the invention.

Of the drawings:

Fig. 1 is a view in end elevation of a mechanism embodying theinvention; and

3 Claims. (Cl. 200-131) Fig. 2 is a view partly in elevation and partlyI in section looking at Fig. 1 from the right.

Objects of the invention are to provide extremely accurate temperaturecontrol means over a very broad temperature range, to provide a type ofconstruction having the greatest strength. stiiinesa-and rigidity ofmoving parts, coupled with compactness, to provide a mechanism adaptedto operate one or a plurality of energizing switches and to provide amechanism attaining the foregoing objects which is simpler, moreaccurate, and cheaper to manufacture than devices heretofore used forthe same general purposes.

Referring in detail to the embodiment of the present invention as shownby way of example in the accompanying drawings, the temperature in achamber is controlled by a switch governing device mounted in a casing loutside the chamber and comprising a base plate 2 and an end plate 8. Apivot 5 is mounted by suitable means on a base casting 6. A'switchbearing lever I and a switch controlling lever 8 are rotatably mountedon said pivot I. A coil spring I0 is mounted compressibly between theswitch controlling lever 8 and the switch bearing lever I. Said springis mounted in a cylindrical recess I! in the switch controlling lever 8and against the end wall lie! the switch bearing lever 1. The portion ofthe Spring I8 between the recess ll and the end wall 15 is clampedbetween the sides ii of the switch bearing lever 1. Adapted to bearagainst and actuate the switch controlling lever 8 is a temperatureactuated rod member i8 of a temperature sensitive mechanism (not fullyshown) which mechanism is located within the chamber of which thetemperature is to be controlled. Said rod member l8 bears against thelever 8 at a point relatively close to the pivot 5 causing said lever tobe especially sensitive to any mo"ement oi the rod member l9. Bearingagainst and adapted to move the end wall I5 of the switch bearing leverI is a threaded rod 24 threadedly mounted in the base casting 6,extending through the casing l and bearing a dial 25 on its externalend.

At the portion oithe switch bearing lever I distal to the pivot 5 ismounted a switch 28, which may be a conventional microswitch for openingand closing a temperature changing circuit (not shown). Said switch, ofcourse, includes an actuating member 28 which opens and closesthecircuit. At the end 01' the switch controlling lever 8 distal to thepivot 5 is mounted a calibrating stud 82 which is threadably engagedwith said lever 8 and extends therethrough, and is adapted to be held infixed relation therewith by means of a locknut 83, or locking screw 80.

In the embodiment shown the levers 8 and 1 are so designed, and theswitch 28 and calibrating stud 32 are so mounted thereon that theactuating member 29 of the switch 28 and the cooperating portion of thecalibrating stud 82 are tangent to a circle about the center of thepivot 5.

In operation the threaded rod is adjusted so as to limitcounter-clockwise movement of the switch bearing lever I. Said lever 1,when the device is in operating adjustment, is springably restrainedfrom clockwise rotation by the spring iil which is based at the end ofthe recess IS in the switch controlling lever 8. The switch controllinglever 8 in turn tends to be urged in clockwise rotation by spring ill,but is prevented from clockwise movement by the temperature actu-, atedrod member l8. Thus, when the inner end of the rod member I! is urgedagainst the switch controlling lever 8 said lever will rotate countercockwise permitting the switch actuating member to raise to one operatingposition. When the end of the rod member ID tends to move away from theswitch controlling lever 8, the call-- brating stud 82 will depress theactuating member 29 to another operating position. For ex ample, the rodmember i 8 may be a relatively non-thermally expansible member within athermally expansible tube. Upon an increase of temperature within thechamber the tube would expond and the rod l9 would move away from theswitch controlling lever 8, and vice versa. The switch 28, of course,may be a normally open or a normally closed type.

Devices embodying the present invention may be used for a one switchinstrument, a two switch instrument, or a threeswitch instrument. Whenused as a one switch instrument the extensions on the switch controllinglever I are omitted. n usi g a two switch instrument I have foundparticularly suitable an oflset switch controlling lever with thecalibrating studs located on either side of the midline of the lever.

Because of the fact that the spring I is recessed in the switchcontrolling lever I a long spring may be used giving an adjustable rangemuch broader than other instrumentsoi this type permitting controlthrough practically the entire temperature range b one instrument.

The design and construction of the switch bearing lever of theembodiment of the invention shown in the accompanying drawings gives thegreatest strength, stiifness and rigidity to hold the switch 28 whileoccupying a very small space. These desirable results are brought aboutin great part due to the box construction formed by the switch 28 beingclamped between the sides 18 or the switch bearing lever 1.

In the embodiment shown the dial 25 is of the vernier type, allowingimproved sensitivity and accuracy of adjustment control.

The invention in its broader aspects is not limited to the specificmechanisms shown and described but departures may be made therefromwithin the scope of the accompanying claims without departing from theprinciples 01' the invention and without sacrificing its chiefadvantages.

What I claim is:

1. A mechanism for controlling temperatures in controlled temperaturechambers comprising in combination a casing located externally oi. thechamber, a temperature actuated device mounted in said casing andextending into said chamber, an adjusting screw mounted on said casing,

a switch lever and a switch-controlling lever pivotally mounted in saidcasing on a common pivot, said switch-controlling lever being inengagement with said temperature actuated device, a spring mountedagainst said switch lever and said switch-controlling lever and tendingto move said levers about their pivot in opposite directions to holdsaid switch lever against said sdjusting screw and to hold saidswitch-controlling lever against said temperature operated device. saidspring being inserted in a recess in said switch-controlling lever.

2. A mechanism for controlling temperatures in controlled temperaturechambers comprising, in combination, a casing located externally of saidchamber, a temperature actuated device mounted in said casing andextending into said chamber, an adjusting screw threadably mounted insaid casing, a switch lever and a switch controlling lever pivotallymounted on a common pivot within said casing, said levers bearingrespectively a switch having an actuated member and a switch actuatingmember, the actuated and actuating members of the lever; being in a linetangent to a circle about the center of said pivot, a spring recessed insaid switch controlling lever, and bearing against said switch bearinglever tending to urge the switch bearing lever against the adjustingscrew and said switch controlling lever against said temperatureactuated device.

3. A mechanism for controlling temperatures in controlled temperaturechambers comprising, in combination, a casing located externally of saidchamber, a temperature actuated device mounted in said casing andextending into said chamber, an adjusting screw threadably mounted insaid casing, a. switch lever and a switch controlling lever pivotallymounted on a common pivot within said casing, a spring recessed in saidswitch controlling lever, and bearing all-inst said switch bearing levertending to urge the switch bearing lever against the adjusting screw andsaid switch controlling lever against said temperature actuated deviceat a point relstively close to the pivot.

HERBERT B. BURLING.

